Ultra-low-loss optical fiber nanotapers

TLDR

Optical fiber tapers with waist sizes larger than 1 µm are common in telecommunications and sensing, yet fabricating low‑loss subwavelength tapers was considered impractical due to surface roughness and diameter uniformity challenges. The study shows that very‑long ultra‑low‑loss tapers can be produced using a conventional fiber taper rig with a simple burner configuration. The method employs a conventional taper rig and a simple burner configuration to achieve these tapers. The tapers exhibit single‑mode losses at 1.55 µm that are an order of magnitude lower than previously reported, SEM images confirm excellent uniformity, and these low‑loss structures should enable a range of fiber nanodevices.

Abstract

Optical fiber tapers with a waist size larger than 1microm are commonplace in telecommunications and sensor applications. However the fabrication of low-loss optical fiber tapers with subwavelength diameters was previously thought to be impractical due to difficulties associated with control of the surface roughness and diameter uniformity. In this paper we show that very-long ultra-low-loss tapers can in fact be produced using a conventional fiber taper rig incorporating a simple burner configuration. For single-mode operation, the optical losses we achieve at 1.55microm are one order of magnitude lower than losses previously reported in the literature for tapers of a similar size. SEM images confirm excellent taper uniformity. We believe that these low-loss structures should pave the way to a whole range of fiber nanodevices.